[Preoperative diclofenac does not reduce pain of laparoscopic cholecystectomy]

To study the safety and efficacy of diclofenac for preemptive analgesia in the first 24 hours after elective laparoscopic cholecystectomy (ELC).

This prospective, randomized, placebo-controlled, double-blind study enrolled 90 patients of both sexes undergoing ECL. The patients were 17 to 76 years old and weighed between 45 and 100 Kg (ASA I and II). Assignment was to one of the following groups. A control group received diclofenac before and after surgery (DD) as follows: diclofenac 1 mg/Kg i.m. 60 minutes before surgery and a loading dose of 0.35 mg/Kg i.v. after surgery followed by continuous infusion of 1.5 mg/Kg over 24 hours. The study group received diclofenac and placebo (DP) as follows: diclofenac 1 mg/Kg i.m. 60 minutes before surgery and infused saline solution after extubation. A second control group received placebo before surgery and diclofenac afterwards (PD) as follows: a physiological solution was given intramuscularly 60 minutes before the operation and diclofenac was given after extubation as in the DD group. Pain intensity was assessed on a visual analog scale at four times: 1 hour (T1), 6 hours (T2), 12 hours (T3) and 24 hours (T4) after extubation. At those times we also recorded the need for rescue analgesia and side effects. Arterial blood gases and vital signs were recorded 1 hour before surgery (T0) and at T4.

Pain intensity at T1 was 2.67 +/- 0.54, 2.82 +/- 0.63 and 2.88 +/- 0.58 for the DD, DP and PD groups, respectively (p = 0.96). The differences in mean pain between T1 and T2, T3 and T4 were -0.2 +/- 0.66, -0.7 +/- 0.51 and 0.0 +/- 0.72 in the DD group (p = 0.723); -0.9 +/- 0.60, -0.4 +/- 0.57 and -1.3 +/- 0.65 in the DP group (p = 0.578); and -1.0 +/- 0.59, -0.5 +/- 0.77 and -1.0 +/- 0.69 in the PD group (p = 0.816). No significant differences in pain intensity or need for rescue analgesia were observed. Although 22 side effects were observed in group DD, 21 in DP and 21 in PD, none was serious.

Simple preemptive analgesia with 1 mg/Kg i.m. of diclofenac 60 minutes before induction of anesthesia does not decrease pain intensity or the need for rescue analgesia in the first 24 hours after ELC.